a. Field of the Invention
The present invention pertains generally to serial communications and specifically to three wire handshaking and data transfer between multiple devices.
b. Description of the Background
Communication between multiple independent electronic devices is typically needed for many different applications. For example, communications between a controller device and one or more slave devices enables a system designer to split the functions of the entire system into manageable parts. These parts may be independent and individually replaceable. In addition, the use of one controller and multiple identical slaves may reduce the cost of the slave units by taking advantage of economies of scale.
Several communications protocols already exist, including the Inter-Integrated Circuit (‘I2C’) protocol developed by Philips. One of the limitations of the I2C protocol is that a slave cannot initiate communications with the master. However, the master may request information from a slave. Further, the cable length between devices may be an issue with the I2C protocol.
It would therefore be advantageous to provide a communication protocol that allows two way communication between a large number of devices. It would be further advantageous to provide a protocol that may be implemented over long distances.